SU1748003A1 - Method and device for determining cord residual strength realization - Google Patents

Abstract

The invention relates to a test unit and allows determination of the residual strength of one-dimensional samples of materials, preferably a para-slug sling. The purpose of the invention (method) -1 is an increase in the exact determination of the residual strength of dynamic loading by eliminating the rest effect of the material of the sling. The residual strength is determined by dynamically applying a load to the sling during cyclic loading at the moment the corresponding fatigue damage occurs. The purpose of the invention is to approximate the determination conditions to the operating conditions of the parachute slings, noise reduction and increased i.e. the durability of the device, Active grab 1 is reported to be a cycle cal movement with an amplitude and frequency corresponding to the real, via drive 7, the eccentric 5, and b korsmysla rod 4 loads 10 via the flexible element 9 and passive grip 3 sling 2 further loaded real static force. After a certain actual time condition for cyclic loading of the sling 2 by the signal, the load 15 is released from the communication by the flexible element 16, falls on the noise-absorbing pad 12 of the magnetic stop 11 and causes the sling 2 to collapse. The loads 10, 15 and the stop between them are almost without noise and damage. shock absorber 13 installed ha base 14, 2 with p f-ly, 2 silt

Description

The invention relates to a test technique and makes it possible to determine the residual strength of one-dimensional samples of materials, preferably a parachute sling.

The purpose of the invention (spbsoba) is to improve the accuracy of determining the residual strength in the process for dynamic loading by eliminating - the effect of rest of the material of the sling

The method is carried out as follows.

Cycles of a varied tensile load are applied to the parachute sling and the material of which it is made is applied to the parachute. During the loading process, at the time corresponding to the specified operating time of the installed damage in the material of the sling, a destructive effect is applied to it suddenly or dynamically. tensile load and determine the value of the residual strength of the material parachute slings

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The purpose of the invention (device) is to approximate the determination conditions to actual conditions of operation of the parachute slings, reducing the noise level and increasing the durability of the device.

FIG. 1 shows a diagram of the described device; in fig. 2 - the same, at breakage of the sample.

The device contains an active grip 1 of the line 2, a passive gripper 3 installed by the coaxially active line 3 of the line 2, a mechanism for cyclic movement of the active device 1, made in the form of a rod 4 rigidly connected with it, an eccentric 5, a rocker arm 6, an articulated rod 4 with an eccentric 5 and the actuator 7 for rotation of the eccentric 5, the residual deformation compensator of the sling 2, worn out in the pide of the guide roller 8, the flexible element 9 thrown through it with a load 10 at one end and connected to the other; they are passively gripping 3 and an elliptical stop 11,mounted on a flexible element 9 between the load 10 and the guide roller 8, a noise absorbing gasket 12, is installed: facing the guide roller 8 along the amphibiousness of the stop 11, the shock absorber 13 of the load 10, mounted on the base 14, located between with a supporting roller 8 and an anvil 11 with the ability to move an additional axillary-out of the ferromagnetic material 1-iaa 15 with an axial bore, through which the flexible element 9 passes, an additional flexible element 16 with the release lock 17, P designed to hang a load 15, and a strain gage 18 with a device 19 for registering its signals. Load 15 has a guard that prevents it from falling onto the load 10

The device works as follows.

The size of the load 10 is selected from the conditions of the actual loading of the sling 2 parachute Adjusting the eccentric 5 sets the amplitude of the deformation of the sling 2 corresponding to the real Turn on the rotational drive of the eccentric 5 and set the speed of rotation of the sling 2 corresponding to the real one.

After a certain time of cyclic loading of the sling 2, selected from the actual conditions of the parachute, without interrupting the cyclic loading, a command is issued to trigger the release 17, and the additional load 15 is released from the connection of the additional flexible element 16, falls along the flexible element 9 and the impact em on noise-absorbing gasket 12 magnetic stop 11 Additional load 15 of ferromagnetic material with

pulling with magnetic stop 11. The amount of additional weight 15 is preselected such that when it strikes a noise absorbing pad 12, the sling collapses 2 times. Destruction load

the slings 2 is fixed with strain gauges i-18 and the device 19 for recording its signals

After the destruction of the sling 2, the load 10 is practically without noise and damage is lowered onto the shock absorber 13 mounted on the base 14, wherein the additional load 15 together with the magnetic stop 11, not reaching the load 10, is also practically without noise and without damage hangs on the stopper, the flexible element 9 between the load 10 and the stop 11 forms a slack.

Claims (2)

1. Method for determining residual The strength of the Napai Utah sling, which consists in applying a cyclic load to the sling and determining its strength, corresponding to the accumulated number of loading cycles, is also distinguished by the fact that, in order to improve the accuracy of determining the residual in the process of dynamic loading by eliminating the effect of rest the material of the sling, in the process of loading at a time, corresponding to the accumulation of fatigue damage te material of the sling, a destructive load is dynamically applied to it, taking into account full strength. 2. A device for determining the residual strength of a parachute sling, containing an active grip of the sling, associated with it vpxahnsM cyclic movement, passive grip, mounted coaxially with active, and residual strain compensator of the sling, made in the form of a guide roller, a flexible element thrown over it with a load at one end and connected to the other end with a passive grip, characterized in that, in order to bring the determination conditions to real conditions of operation parachute slings, reducing noise and increasing the durability of the device; it is equipped with a magnetic stop mounted between the load and the guide roller, a noise-absorbing gasket mounted on the A roller of the stop surface, a weight shock absorber and located between the guide roller and the stop, with the possibility of moving an additional axisymmetric load of ferromagnetic material with an axial bore through which the flexible element passes before the impact of the noise absorbing pad. 777777/7 // 777 / 7Я777 //, W. / 15 “,. sz 10 1 13 fj ™,,. У7Г7Ъ 77Г УГ77 7 Vi five uff g